2008 Chevy Silverado Dodge Ram Ford F-350 - Ultimate Tow-Rig Test

This Is The Beginning Of What's Sure To Be a decade of huge changes in the automotive landscape. Soaring oil prices and growing concerns about global warming are prompting the government to enact ever-stricter regulations in the areas of fuel economy and emissions. Those regulations are pushing automakers to find cleaner and more efficient ways to power our vehicles.

Bringing up the curtain on this new age of efficiency was the EPA's mandate to replace conventional diesel fuel with ultra-low-sulfur diesel (ULSD) as a means of reducing diesel emissions. It's a rolling change that will take several years to fully implement, but automakers and truckmakers were among the first to feel its effects when they were asked to deliver ULSD-burning vehicles to market by January 1, 2007. This meant Chrysler, Ford, and GM had to redesign or revamp the diesel engines for their heavy-duty pickups to meet that deadline. In essence, the world of diesel-powered haulers changed almost overnight.

We can't remember when (or if) an entire truck segment went through this kind of change all at once, and it seemed like the perfect opportunity for a comparison test of the new diesels. But what kind of test? We discussed including them in our annual 4x4 of the Year competition, but soon realized that test is too trail-oriented to truly evaluate these trucks' attributes. No, this called for something different, a test that borrows some of the 4x4 of the Year's structure but takes place on the kinds of terrain that would typically be encountered by big diesel 4x4 haulers.

What we came up with is a comparison test to approximate what a truck owner would experience if he or she bought a diesel pickup to tow a trail rig. We planned driving routes in some of the toughest tow country in our neck of the woods: the highways and two-lanes in the hills around the Tejon Pass, better known as the Grapevine. What's so tough about it? Well, for starters, there's the altitude. Most of our testing took place between 3,000 feet and the 4,144-foot summit. There's very little flat ground south of the Pass, so the constant up- and downhill driving would test power delivery and braking ability alike. Also, there's always a huge amount of traffic flowing through this area (it's the major north-south artery linking Southern California with the rest of the state), so merging with traffic would test not only vehicle power but also visibility. And finally, nestled in these hills is the Hungry Valley SVRA, where we could put these rigs on graded dirt roads and trails to simulate travel to a trail head.

We worked hard to keep this test as apples-to-apples as possible. We asked the manufacturers for similarly equipped trucks-all '08-model 1-ton, crew-cab, dual-rear-wheel, 4x4 diesels equipped with the maker's towing packages-and we're proud to say that we're the only magazine that assembled such a fleet. (Other magazines that have printed similar tests did so with a mix of single- and dual-rear-wheel trucks.) During our back-to-back evaluations, all three trucks traveled the same roads and trails on the same days, with testdrivers switching among them to drive and then recording their impressions in notebooks. To keep the towing comparisons consistent, each truck towed the same piece of equipment: our Ultimate Adventure Jeep Wrangler lashed to a flatbed trailer. The 9,800-pound load was heavy enough to test tow capabilities without surpassing any of the trucks' tow capacities.

When it came time to rank the contestants, the judges (Ali Mansour, Fred Williams, and yours truly) scored each truck in a number of categories using a 0-5 scale, with 0 being hateful and 5 being best. We allowed more than one truck to get the same score in a category (if all three were equally quiet at idle, for example, they could all score 5s), which resulted in tie scores in some individual categories.

When all the votes were in, however, there was no tie. One truck won enough categories outright and scored highly enough in the others to claim victory. Read on to see which of the new, clean-diesel pickups earned our first Ultimate Tow Rig title.

It May Seem Strange To Describe A 1-ton truck as carlike, but the Chevy was the most carlike on the test. Its 6.6L Duramax diesel produced the most top-end horsepower, so much so that we called it the "hot rod" of the test. Dyno pulls confirmed our seat-of-the-pants impression: The Chevy's 294 rear-wheel horsepower easily bested the Dodge's 283 and Ford's 277. We also found that the truck's independent front suspension gave it nice road manners, with a smooth ride and precise handling.

Those same traits, though, can also be negatives. While its high-speed power was good, the Duramax felt like it lacked the bottom-end grunt offered by the others. Again, the dyno confirmed our feelings, with the Duramax's 487 lb-ft of peak torque lower than the 500-plus produced by the others. Our acceleration tests were another indicator: The Chevy was quicker unloaded, but the Dodge beat it pulling the trailer.

And it will probably come as no surprise that the Chevy's IFS proved to be a weak spot off-road, hampering the truck's ground clearance and, in one judge's opinion, its on-dirt handling. Also impeding its off-road performance were low-hanging framerails and the Chevy's street-oriented (and too small) LT225/75R17 General Grabber tires.

We also had a problem with the Chevy's outside mirrors. While big, vertical trailering mirrors are available on the truck, ours was fitted with the standard mirrors, a real head-scratcher given all the other trailering equipment loaded on this rig.

The Chevy proved to be a good towing platform. It was stable on- and off-road, it had plenty of power, and its Allison six-speed transmission was well matched to the Duramax. Its tow/haul mode kept the engine speed where we wanted it, except through long downhill stretches, where it wouldn't hold its speed without help from the brakes.

Front-seat passengers will find the Chevy inviting, with supportive seats and plenty of room. Back-seat passengers, on the other hand, will suffer from seats that are too firm and too upright, though there is plenty of room back there, too. We all felt the Chevy's dash and controls were a little too complicated and hard to use.

Though it sounds like we found a lot to dislike about the Chevy, the whole is actually a better truck than the sum of its parts. When asked which of the three trucks they'd like to own, two of the three judges chose the Chevy because of its power, ride quality, interior comfort, and "rugged and burly" styling.

Engine notes: Modifications to this (LMM) version of the Duramax included new fuel injectors to improve atomization, a ceramic-type diesel particulate filter system to reduce particulate emissions, and a change to the turbocharger's compressor bore to improve its durability.

If The Chevy Silverado Was The Car in this test, the Dodge Ram was the workhorse. The 6.7L Cummins produced the most torque-on the chassis dyno if not on paper-and it felt like it, as this truck pulled like the proverbial locomotive from any stop. It was the tallest of the three, feeling like it already had received a mild lift. And the Ram had the most trucklike ride, a harsh bump-and-jounce that rattled your skull on dirt and asphalt.

Towing did settle the rear suspension, maybe a little too much, in fact. One judge wrote that the Ram's rear "felt slightly soft when towing, where the Ford was too stiff and the Chevy just right." Another noted that the Ram was the only truck that felt noticeably lighter in the front when pulling the loaded trailer.

Though we weren't fans of the Ram's ride quality, we did love its solid front axle and abundant ground clearance when on trails. Transitions from dirt to pavement-which can be tricky when towing-were made easier by excellent articulation and the hard-working limited-slip in the rear diff. About the only thing we could have asked for off-road was a set of more aggressive tires.

When towing, the Ram lacked nothing in terms of equipment. You could rotate its big outside mirrors from horizontal to vertical to improve vision, the tow-haul mode in the 68RFE six-speed would automatically downshift to help slow the rig when coming to a stop, and the Cummins' factory exhaust brake (actuated by a dash-mounted button) ensured that the truck and trailer maintained our desired speed down every grade. In fact, we just left the exhaust brake on whether we were trailering or not. It was that effective, and that cool.

The Ram wasn't perfect. While it had great off-idle torque, the Cummins felt like it ran out of steam climbing and passing-a feeling that, admittedly, wasn't reflected on the clocks during our acceleration tests. We also noticed that when the truck was unloaded, the transmission always wanted the highest gear possible. That may be good for fuel economy, but we always had to kick the accelerator, sometimes hard, to find the right gear for passing.

Because we got the Mega Cab version of the Ram, it was the one truck on the test without a longbed. (That combination isn't available.) In-cab storage is plentiful and thoughtful. We also appreciated the simple dashboard layout, which made the other trucks' instrument panels look needlessly complex. Our one gripe about the Dodge's interior: the flat, unsupportive seats.

Engine notes: This new version of the Cummins I-6 has grown considerably, from 5.9 to 6.7 liters, and its power output has grown too, from 325 to 350 hp and 610 lb-ft of peak torque to 650. Dodge says 40 percent of the new engine's parts carry over from the older version, with most of the modifications aimed at increasing power and cleaning emissions. The equipment on the Cummins allows it to meet the EPA's 50-state truck standards for 2010-the only truck to do so.

If The Chevy Was This Test's Hot Rod, and the Ram the workhorse, the Ford took its place on the deluxe end of the spectrum. Credit goes to the King Ranch package, with its two-tone paint, polished aluminum wheels, four captain's chairs and saddlelike leather on the seats, consoles, and steering wheel. "The interior is pretty cowboy, almost too much," wrote one judge, "but it grows on ya."

When it was time to tow, though, the Ford was all business. The new 6.4L Power Stroke delivered almost as much torque as the Cummins, making for strong trips up onramps and away from stoplights. The truck was more stable when towing than the Dodge and on par with the Chevy's stability. Rearward visibility was excellent, thanks to Ford's PowerScope rearview mirrors, which are motorized to extend away from the body and also feature a generous convex mirror along the bottom.

One flaw that surprised us about the Ford's powertrain was its lack of top-end power, which caused the truck to struggle when passing. Since the Power Stroke is the only diesel of the three with twin, sequential turbochargers, we felt it should deliver better mid- and high-end grunt.

Off-road, that lack of top-end power proved to be a nonissue, as the engine's ample torque pulled the trailer along easily. The solid-axle suspension worked well through ruts and gullies, helped by the BFG Rugged Trail tires. As it turned out, Ford was the only maker to put all-terrain tires on its truck. True, Rugged Trails aren't the most aggressive rubber, but they looked like Super Swampers compared to the street meats on the other trucks.

At $57,000-plus, the Super Duty was the most expensive truck in this test. Ordering it without the $3,600 King Ranch package would bring its price in line with the others, and you'd get a less fancy interior and a more utilitarian rear bench seat.

Engine notes: Unlike the Duramax and Cummins engines, the 6.4L Power Stroke is a "clean sheet" design. Ford engineers put some 10 million test miles on the engine, on the road and on dynamometers, "using the most extreme and abusive conditions and run to five-times the life cycle that the hardest-working truck would ever experience," said Ford.

The Power Stroke shares many of the emissions devices used on the other engines, including a particulate filter and an oxidation catalyst. Unlike the others, though, turbocharging is done via twin sequential turbos-a small, variable-geometry one to provide low-speed boost, and a second, larger, fixed turbo that comes on in the engine's mid-range and continues to boost through the higher rpm.

To maximize the "real world" nature of this comparison test, most of the instrumented testing was done on an empty, uphill road using a GTech Pro RR performance meter to record the data. We chose this stretch of road to approximate the uphill onramps common to this portion of Interstate 5, figuring it would be more instructive to measure how well the trucks performed under challenging conditions rather than on an easier-to-negotiate flat road (or dragstrip). The "time to pass" tests were performed in traffic on the Interstate, again in a hilly area, using a stopwatch to record how long it took to pass a vehicle-in this case another test truck holding a steady 60 mph. To keep the testing as consistent as possible, all runs were done using Fred Williams as stunt driver.

Fuel used for the test was ultra-low-sulfur diesel sold at Union 76 and Chevron stations in Southern California. It was not supplied to us but was purchased at retail. Diesel prices during our late-November 2007 test period ranged from $3.299 to $3.659 per (self serve) gallon.

Rear-wheel power data was measured on an in-ground DynoJet chassis dynamometer by the technicians at DC Performance in Los Angeles (310.841.6996, www.dcperformance.com).

JUDGING RESULTS

CHEVY

DODGE

FORD

1. Drivetrain

131

127

112

2. Ride & Handling, On-Road

128

113

120

3. Ride & Handling, Off-Road

119

118

126

4. Interior

122

120

128

5. Exterior

38

38

34

6. Towing Attributes

25

51

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7. Off-Roading Attributes

34

49

48

8. Styling

24

26

23

TOTALS

621

642

648

We would like to thank Mac's Custom Tie Downs for supplying us with a new set of trailer tie-downs for this test. We've been using a set of Mac's tie-downs for more than a year now and they have worked great, but the grease and abuse from hauling all sorts of project trucks and other junk on the trailer was making them pretty ugly. Mac hooked us up with its Ultra Pack in 4-Wheel & Off-Road red. This set comes with two 6-foot and two 8-foot ratchet straps, along with four axle straps, all in a duffle bag. The 10,000-pound capacity is perfect for even our biggest trail rigs.

They were all good; the ford was better.When Ford delivered the Super Duty test truck to us, it seemed to have two strikes against it from the start. This truck had been in the press fleet for a while, and it had racked up more than 21,000 miles performing for various magazines. Since press fleet miles are sort of like rental-car miles (can you say "accelerated wear"?), we were unsure how much life was left in the ol' F-truck. We were also concerned when we spotted a fifth-wheel gooseneck hitch taking up most of the bed, wondering how much the weight of that gear would affect the truck's performance.

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Turns out we needn't have worried. This is a diesel, after all, and 21,000 miles-even in dog-year, press-fleet terms-isn't even close to broken in, let alone tired. And while the weight of the gooseneck may have slowed the truck some, it didn't do irreparable harm.

One look at the scoring results will tell you this was a close race. As Fred Williams wrote in his judging sheets, "Any of these trucks would be perfect for me. All tow great and are comfortable to spend hours in during long trips. Some are just a little better in certain areas."

That describes the Super Duty's victory perfectly. It was by no means a slam-dunk. In fact, we were all a little surprised when the Ford came out on top. The carlike nature of the Chevy and the work-truck persona of the Dodge left more of an impression on all of us than the deluxe cruiser that was the Ford. That the Power Stroke didn't perform as well as we anticipated seemed to doom the Super Duty to also-ran status.

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Then again, the Ford did come out on top in some key categories. As much as we mocked the big-belt-buckle fanciness of the King Ranch interior, the Ford's cockpit was a comfortable, well-laid-out place to spend time. Its suspension was supple enough and its BFGs grabby enough for the truck to top the off-road ride and handling portion of the test (and nab second in the on-road segment). And then there were its towing attributes: those wonderful PowerScope mirrors, a nicely designed trailering package (complete with trailer brake controller), and a reversing sensor to alert you when you were close to the trailer's tongue.

This was, after all, a test of tow rigs. The Ford wasn't the fastest or the most powerful truck of the three. But it was fast enough, and powerful enough, and when you put those traits together with a very stable, well-handling towing platform with mirrors that allow you to move around in traffic with full confidence, then you have a truck worthy of being called our Ultimate Tow Rig. Congratulations, Ford.